1. Field of the Invention
The present invention relates generally to solar battery modules and particularly to those fabricated by a process with a simplified interconnection step, providing improved insulation as a solar battery module and improved in design, and methods of fabricating the same.
2. Description of the Background Art
A conventional solar battery module is structured, as shown in FIGS. 13A-18C.
A solar battery module 1 is structured as follows: a plurality of solar battery cells 11 (nine cells in this example) are linearly arranged and electrically connected by a connection member 12 to form a cell unit (hereinafter referred to as a xe2x80x9cstringxe2x80x9d) 13. A plurality of strings 13 (six strings in this example) are arranged laterally side by side and solar battery cells located at opposite ends of the cell units and adjacent to each other (cells 11a1 and 11a2, 11b1 and 11b2, 11c1 and 11c2, 11d1 and 11d2, 11e1 and 11e2) are electrically connected by a connection member 14 to allow a matrix of solar battery cells (hereinafter simply referred to as a xe2x80x9cmatrixxe2x80x9d) 15 to be entirely connected in series.
Then, as shown in FIG. 16, matrix 15 thus electrically connected has a lower surface with a sheet of filler resin (e.g., ethylene vinyl acetate (EVA)) 16 and a rear cover (a back film) 17 arranged adjacent thereto and also has an upper surface (a light receiving surface) with a sheet of filler resin (e.g., EVA) 18 and a front cover (of glass) 19 arranged adjacent thereto, with their respective peripheries together surrounded by a frame member of aluminum 20 (see FIG. 18B). Rear cover 17, front cover 19, filler resin 16, 18 and frame member 20 ensure strength, moisture resistance, and insulation.
Solar battery module 1 structured as above is fabricated, as follows: as shown in FIG. 13A, nine solar battery cells 11 are arranged linearly (laterally in a row) and cells 11 adjacent to each other are connected together by connection member 12 in order electrically to form string 13.
FIG. 14A is a cross section of FIG. 13B taken along a line XIV-XIVxe2x80x2, showing a portion of string 13, as seen laterally. Connection member 12 has a buckle 12a substantially at its center. Buckle 12a corresponds to a thickness of solar battery cell 11. Via buckle 12a one portion for connection 12b is connected to solar battery cell 11 on a front side (the side of a negative electrode) 11a and the other portion for connection 12c is connected to an adjacent solar battery cell 11 on a bottom side (the side of a positive electrode) 11b. As shown in FIG. 14B, connection member 12 is a copper wire in an elongate plate having a surface plated with solder and it has a width of approximately 1.5 mm and a thickness of 0.15 mm.
Six of such strings 13 are arranged laterally side by side and the solar battery cells located at opposite ends of the strings and adjacent to each other (cells 11a1 and 11a2, 11b1 and 11b2, 11c1 and 11c2 , 11d1 and 11d2, 11e 1 and 11e2) are electrically connected together by interconnection member 14 to fabricate matrix 15. Interconnection member 14 is also a copper wire in elongate flat plate having a surface plated with solder and two types thereof are prepared, one having a width of approximately 1.5 mm and a thickness of 0.15 mm and the other having a width of approximately 6 mm and a thickness of approximately 0.23 mm.
FIG. 15 shows solar battery cells connected together by interconnection member 14, as seen in matrix 15 from a lower side.
More specifically, from a reel of a flat copper line of approximately 1.5 mm in width and a reel of a flat copper line of approximately 6 mm in thickness the copper lines are extracted and each cut to have a required length to form interconnection member 14 required for connection. Note that in cutting interconnection member 14 out, five first pieces for linkage 14a, 14axe2x80x2 . . . are cut from the 6 mm width flat copper line for laterally connecting adjacent solar battery cells (11a1 and 11a2, 11b1 and 11b2, 11c1 and 11c2, 11d1 and 11d2, 11e1 and 11e2) together and ten pieces for protrusion 14b, 14bxe2x80x2 . . . are cut from the flat copper line of 1.5 mm in width and 0.15 mm in thickness for connecting the first piece for linkage 14a, 14axe2x80x2 and an electrode of the bottom side of each of positionally lower ones 11a2, 11b2, 11c2, 11d2 and 11e2 of the adjacent solar battery cells.
Furthermore, in FIG. 15, two second pieces for linkage 14c are cut from the flat copper line of 6 mm in width and 0.23 mm in thickness to provide a lateral connection between an electrode of the bottom side of solar battery cell 11f and an electrical output port 15a provided on one side of matrix 15 at a center, formed at rear cover 17, and between the other portion for connection 12c of connection member 12 attached to solar battery cell 11g and an electrical output port 25b provided on one side of matrix 15 at a center, formed at rear cover 17, and two pieces for protrusion 14d are cut from the 6 mm width flat cover line to provide a connection between the second pieces for linkage 14c tips and electrical output ports 25a, 25b. Furthermore in FIG. 15 two pieces for protrusion 14b are cut from the flat copper line of 1.5 mm in width and 0.15 mm in thickness to connect the second piece for connection 14c and an electrode of the bottom side of solar battery cell 11f. 
Furthermore in FIG. 15 two pieces for protrusion 14e are cut from the 6 mm width flat cover plate for connection to the first pieces for linkage 14a at their respective ends closer to the center to connect a bypass diode (not shown) in a vicinity of electrical output ports 25a, 25b. 
All the required members (pieces) cut from the flat copper lines for interconnection member 14 are then soldered for example with a soldering iron in order.
More specifically in FIG. 15 each of the three first pieces for linkage 14a and the two pieces for protrusion 14b are soldered together and thus joint generally in a letter F inverted and upside down. Then each of the first pieces for linkage 14a with pieces 14b is arranged along a right-hand edge of matrix 15, and a portion thereof for connection opposite that has two pieces for protrusion 14b connected thereto with solder and the other portions for connection 12c of connection member 12 attached to a respective upper one of the adjacent solar battery cells, i.e., cells 11a1, 11c1, 11e1 are soldered and thus connected together, and the pieces for protrusion 14b and an electrode of the bottom side of each of lower ones of the adjacent solar battery cells, i.e., cells 11a2, 11c2, 11e2 are soldered and thus connected together.
Furthermore in FIG. 15 the two first pieces for linkage 14axe2x80x2 arranged at the center and two pieces for protrusion 14bxe2x80x2 are soldered and thus connected in a letter F inverted and upside down, and each piece 14axe2x80x2 has a tip with a piece for protrusion 14e soldered and thus bonded thereto for connecting a bypass diode. Each piece 14axe2x80x2 with pieces 14bxe2x80x2 and 14e is arranged along a left-hand edge of matrix 15, and that portion of the first piece 14axe2x80x2 for linkage which is opposite that having pieces 14bxe2x80x2 soldered and thus connected thereto and the other portions for connection 12c of connection member 12 attached to a corresponding one of upper ones of the adjacent solar battery cells, i.e., cells 11b1, 11d1 are soldered and connected together, and pieces 14bxe2x80x2 and an electrode of the bottom side of a corresponding one of lower ones of the adjacent solar battery cells, i.e., cells 11b2, 11d2 are soldered and thus connected together.
Furthermore in FIG. 15 the second piece for linkage 14c arranged upper than the center of matrix 15 has an upper portion with two pieces for protrusion 14b soldered and connected thereto and a lower portion with a single piece for protrusion 14d soldered and thus connected thereto and the second piece 14c with pieces 14b and 14d is then arranged along matrix 15, and pieces 14b are soldered and thus connected to an electrode of the bottom side of solar battery cell 11b and piece 14d is guided externally from electrical output port 25a. 
The second piece for linkage 14c arranged lower than the center of matrix 15 has an upper portion with a single piece for protrusion 14d soldered and thus connected thereto and the second piece 14c with piece 14d is then arranged along a lower left edge of matrix 15, and a lower portion of the second piece for linkage 14c and the other portions for connection 12c of connection member 12 attached to solar battery cell 11g are soldered and thus connected together and piece 14d is guided externally from electrical output port 25b. 
Matrix 15 thus has interconnection member 14 connected thereto to electrically connect all of the 54 solar battery cells 11 in series. Note that the other portion for connection 12c after it is soldered and connected has an unnecessary portion (a protrusion) cut and removed.
Note that in FIG. 15 a portion soldered and connected is shown circled. As can be seen from FIG. 15, the conventional fabrication method requires that 42 portions be soldered and connected, one by one manually.
Then, as shown in FIG. 16, rear cover 17, the sheet of filler resin 16, matrix 15, the sheet of filler resin 18 and front cover 19 are stacked in order and they are heated and undergo vacuum lamination to seal solar cells 11. FIG. 17 is a cross section showing an enlargement of a portion of a structure sealing solar battery cell 11. Although not described in the above, the structure has an end sealed with silicone resin 21.
In such a fabrication method as described above, connection member 12 connecting solar battery cells and interconnection member 14 arranged on opposite sides of matrix 15 for laterally connecting solar battery cells are a copper wire in the form of a flat plate plated with solder. This is because connection member 12 and interconnection member 14 are finally sealed by filler resin (EVA resin) 16, 17 and silicone resin 21 and for the facility of an interconnection process by means of soldering a covering for insulation, water proof and the like is not required.
Some solar battery module structures, however, require that interconnection member 14 be arranged at a location short-circuiting with solar battery cell 11 or that interconnection materials 14 be arranged to traverse each other. Furthermore, they require that while rear cover 17 is formed of a conductive member, interconnection member 14 penetrate therethrough or that while frame member 20 of aluminum is used, an electrical output be extracted from an end surface located between front cover 19 and rear cover 17.
In such a case for example if interconnection member 14 needs to penetrate rear cover 17 then, as shown in FIG. 18A, an insulation film 22 is required to surround a through hole 17a for rear cover 17 and be inserted between the interconnection member 14 and solar battery cell 11 to ensure insulation between and interconnection member 14 the solar battery cell 11 and if an electrical output needs to be extracted from an end surface located between front cover 19 and rear cover 17 then, as shown in FIG. 18B, insulation film 22 needs to be inserted at an end of rear cover 27 and also at an internal surface of frame member 20 to ensure insulation between the frame member and interconnection member 14. Furthermore, if interconnection materials 14 need to be arranged to traverse each other then, as shown in FIG. 18C, they are stuck with an insulation tape 23 with a predetermined distance posed therebetween to ensure insulation therebetween. This entails a significantly cumbersome step in a solar battery module production process to ensure insulation between interconnection member 14 and other members.
Furthermore in the conventional fabrication method when six strings 13 are arranged laterally side by side and connected by interconnection member 14 in matrix 15 as many as 42 portions need to be soldered for connection, which is a manual and hence time-consuming step.
The main stream of recent solar battery modules is shifting from conventional, industrial purposes to general, residential purposes, and for the latter purposes, design has been an important issue. Interconnection material 14 is plated with solder, as has been described above, and its surface is silver in color, and silver interconnection member 14 is disadvantageously noticeable relative to a color of a surface of a solar battery module entirely fabricated in black. Accordingly, there is an increased demand for coloring an interconnection member disadvantageously observed in appearance.
Furthermore, typically a solar battery module has an end surface sealed with a member, such as shown in FIG. 17, e.g., silicone resin 21 and filler resin (EVA resin) 16, 17, or other similar material which liquefies once in fabricating the solar battery module. As such, air bubbles form or the material peels off and can result in an insufficiently insulated product.
The present invention has been made to overcome the above disadvantages and it contemplates a solar battery module and particularly to that fabricated by a process with a simplified interconnection step, providing improved insulation as a solar battery module and improved in design, and methods of fabricating the same.
The present invention in one aspect provides a solar battery module having a plurality of solar battery cells linearly arranged and electrically connected together to form a cell unit, more than one cell unit being arranged laterally side by side, either solar battery cells located at opposite ends of the cell units and adjacent to each other or an electrical output port and the solar battery cell being electrically connected by an interconnection member to allow a matrix of the solar battery cells to be entirely connected in series, characterized in that the interconnection member excluding a portion thereof for connection is at least partially covered by a cover member.
Preferably, the interconnection member is a conductive electric wire in a form of a flat plate, the cover member is an insulative member, and the cover member is similar or different in color to or from a member surrounding the cover member.
More preferably, the interconnection member connects adjacent solar battery cells together and the interconnection member excluding a portion thereof for connection is formed in a covered geometry.
Still more preferably, the interconnection member electrically connects the solar battery cell and a terminal external to the electrical output port together and the interconnection member excluding a portion thereof for connection is formed in a covered geometry.
Still more preferably, the interconnection member has a portion for connection either on a piece for linkage of the interconnection member at an interval or protruding from the piece for linkage outwards.
Preferably, the interconnection member is integrally formed generally in a letter L, F or E to match a site for connection.
The present invention in another aspect provides a method of fabricating a solar battery module, comprising the steps of: a) linearly arranging and electrically connecting a plurality of solar battery cells together to form a cell unit; and b) arranging more than one cell unit laterally side by side and electrically connecting either the solar battery cells located at opposite ends of the cell units and adjacent to each other or an electrical output port and the solar battery cell together by an interconnection member, characterized in that the interconnection member is formed to match a geometry of a site for connection and in the step b) the interconnection member thus formed is arranged at the site for connection and a connection terminal of the solar battery cell and a portion of the interconnection member for connection are soldered and thus connected to each other.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.